Mo. Rev. Stat. § 574.075: Drunkenness or drinking in certain places prohibited — penalty.

1. A person commits the offense of drunkenness or drinking in a prohibited place if he or she enters any schoolhouse or church house in which there is an assemblage of people, met for a lawful purpose, or any courthouse, in an intoxicated and disorderly condition, or drinks or offers to drink any intoxicating liquors in the presence of such assembly of people, or in any courthouse.

2. The offense of drunkenness or drinking in a prohibited place is a class B misdemeanor.